Low Temperature Preparation of High Refractive Index and Mechanically Resistant Sol-gel TiO2 Films for Multilayer Antireflective Coating Applications

• Published in: Journal of sol-gel science and technology Vol. 22; no. 1-2; pp. 139 - 150
• Main Authors: Langlet, M, Burgos, M, Coutier, C, Jimenez, C, Morant, C, Manso, M
• Format: Journal Article
• Language: English
• Published: New York Springer Nature B.V 01-09-2001
• Subjects: Abrasion resistant coatings; Antireflection coatings; Densification; Heat treatment; Low temperature; Multilayers; Refractivity; Sol-gel processes; Thin films; Titanium dioxide
• ISSN: 0928-0707; 1573-4846
• DOI: 10.1023/A:1011232807842

TiO2 sol-gel thin films have attracted a large attention for applications which require high refractive index transparent layers. In this work, sol-gel TiO2 layers were prepared by Aerosol-gel deposition followed by a thermal treatment procedure in air. Depending on the experimental conditions, abrasion resistant and high refractive index layers could be obtained after post-treatment at only 110°C. In this paper, the experimental parameters which allow the preparation of functional TiO2 sol-gel layers at such low temperature are discussed. It is concluded that the preparation of high refractive index and mechanically resistant TiO2 layers can be interpreted in terms of competition between polycondensation and densification mechanisms. This result allows to envisage the sol-gel processing at low temperature of multilayer antireflective coatings.